2024 Internship at IIJ Research Laboratory, Tokyo, Japan

(Last updated: 2024-01-18)

The internship program continues in 2024. We're looking forward to your applications.


IIJ Research Laboratory conducts advanced research and technology development on the Internet. The researchers, strongly collaborating with the WIDE Project, were long involved in IPv6 standardization and its BSD stack implementation (KAME project), published well known national Internet traffic measurements and analysis for the last years (MAWI project), endeavored to establish a securer interdomain routing protocol, and to experiment with ecological data centers as well as cloud services.

We are looking for motivated interns who can work with us to accelerate our projects by researching problems, proposing solutions, implementing tools, making various simulations, and so on. By joining us, you can get high quality experience in our research laboratory, can communiate with forefront researchers, have time to discuss with other qualified interns, which will be all benefit to your future carrier plan.

Table of Contents

General Information


Due to the visa requirements, applicants MUST have student status during the internship program, which means you must be officially enrolled at your university while you are in Japan. Students who are enrolled in correspondence courses are not eligible.

Compensation and Working Environment

  • Monthly salary: 250,000 JPY
    For non-residents, income and reconstruction tax at a rate of 20.42% is imposed.
  • Location: Head office, Tokyo
  • Internship duration: 2 months July to August or August to September
  • Hours: Flex time system, core time from 11:00 to 15:30
  • Basic working hours: from 9:00 am to 17:30 pm, interns can decide the working hours.
    • Break time: 1 hour
  • Days off: Saturdays, Sundays and National holidays
  • Allowances
    • Commuting allowance from accommodation to the office: Paid
    • Overtime allowance and remote work allowance: None
  • Round trip flight ticket: Arranged and paid by IIJ
  • Accommodation: Arranged and paid by IIJ
  • Employee accident compensation insurance: Applicable
  • Social insurance (health insurance, employees pension): Not applicable

How to apply

  • To apply for an intern position, submit the following documents at our submission page.
    • 1. CV
    • 2. A cover letter explaining your interest in the job
    • 3. The project name you are interested in
    • 4. A letter of recommendation (if available)
    • 5. Your recent published papers (if available)
  • The deadline for applications is January, 31st, 2024 at 23:59 AoE (Anywhere on Earth). Applications will be reviewed on a rolling basis. We will hold face-to-face or remote interviews with applicants before making a final decision.
  • Either acceptance or rejection notification will be sent to you by email by the end of February.

For accepted applicants


  • Type of visa: Designated Activities Visa, Summer Job
  • The details of the documents regarding visa will be announced by our administrative staff once the duration of internship is fixed.

Overseas travel insurance

IIJ requires the intern to make his/her own arrangements to join an overseas travel insurance plan which covers COVID-19 infection before departure for Japan.

Available Projects

Traffic Measurement and Data Analysis


It is essential for IIJ to understand recent trends in customer traffic.

We will provide an internship student an opportunity to work on a small measurement project, possibly using real-world datasets from IIJ's services, in order to provide practical feedback to IIJ's services.

Possible topics are:

  • development of broadband QoE measurement tools
  • development of monitoring tools for large-scale measurement platforms (e.g. detect outages or identify physical topology from traceroute datasets)
  • the mining of big data, such as the detection and correlation of control and data plane events


We are looking for a graduate student for a two-month-long full-time internship. Candidates should have good skills in computer networking, UNIX systems, and programming as well as oral and written communication skills in English.

For data analysis, skills in machine learning techniques and knowledge of statistics are also required.

To complete a project in two months, a candidate should have substantial experiences in the selected research topic.

Host Researchers

Library Operating System

With the name of specialization, various academic and open source projects invented different shape of network stacks and operating systems. While the specializations avoiding generalization tax solve specific problems of network stack, those are often coupled with the downgraded features due to the specializations, which are hard to recover because the feature richness usually comes with the incremental growth of operating systems.

As a result, there are still serious problems of conventional network stack and library operating systems (or userspace network stacks):

  • network stack ossification (hard to introduce new features), lack of personality
  • lack of generality, resulting no legacy application support
  • simply waste of time (if it is implemented from scratch)

The primary goal of this project is 1) to alleviate the current issue of network stacks, and 2) to retain the feature-richness of the current operating systems by morphing a monolithic kernel into an anykernel implementation (a.k.a. library operating system). The concept of library operating system is not new but it is emerging to address current issues on operating system and network stack.

The objective of this project is to design and develop an implementation of library operating system, Linux Kernel Library (or LKL), to solve aforementioned issues of current operating system.

Possible topics (but not limited to) are:

  • supporting general applications with feature-rich network stack
  • benchmark studies with the implemented software to understand the bottlenecks (incl. comparison with alternatives)
  • container runtime integration


We are looking for graduate students who have the following knowledge and skills.

  • Knowledge of computer science and networking technology (or equivalent)
  • Skills of system programmings in C
  • Knowledge and/or experience of Linux kernel development
  • Knowledge and/or experience of network performance benchmarks
  • Pursuing same/similar area of projects in your current projects

Host Researcher

Security and Fault-Tolerance


Security risks (data tampering, exfiltration, etc.) and failures (crashes, configuration error, etc.) are the norm in distributed systems running over the Internet. It is thus necessary to provide solutions that can limit security risks and maintain the system availability despite the presence of faults, while exhibiting good scalability and performance properties.
The objectives of this internship are two folds: (i) to help our on-going research; and (ii) to develop the research and coding skills of the selected candidate.
This project can lead to publications in a top-level international conference as well as contributions to open-source projects.

Possible topics include:


Candidates should have good programming skills (C/C++, Rust or P4) and some experince in the selected research topic (Trusted Execution Environments, kernel programming and/or networking). Candidates should also have good oral and written communication skills in English.

Host Researcher

Internet Health Report


The Internet Health Report (IHR) leverages data collected by large measurement platforms (e.g. RIPE Atlas, RIS, and RouteViews) to monitor the Internet topology and automatically pinpoint connectivity issues (https://ihr.iijlab.net/). IHR is looking for talented students and skilled programmers to develop new analysis tools and improve the usability of existing tools. This is a great opportunity for students to work with our large datasets and develop practical and open source tools for network operators, researchers, and Internet users.

Possible topics include:

  • Development of monitoring tools for large-scale measurement platforms (e.g. monitoring latencies or identify physical topology from traceroutes)
  • Analysis or applications of IHR results
  • Front-end development: Visualization of IHR results (experience in Javascript required)
  • Back-end development: Near-real time data analysis (experience in python required)


Candidates should have good programming skills (Python or Javascript), and experience with data analysis tools. Knowledge in computer networking is also required. Candidate should have good oral and written communication skills in English.

Host Researcher

External Data Compression Project


This project focuses on utilizing advanced threading and process management for external data compression, specifically targeting cache-oblivious and distributed compression on memory-constrained devices. Leveraging Rust's capabilities for safety and performance, the project aims to develop algorithms that adapt to varying cache sizes automatically and distribute compression tasks efficiently across limited memory devices. These efforts are geared towards enhancing data processing efficiency, reducing memory overhead, and optimizing storage and data transmission in resource-limited environments. Previous works, implemented in C++, have shown promising results in terms of compression ratio and speed, but does not leverage any parallel capabilities. The goal of this internship is to implement a parallel version of the compression algorithm in Rust, and to evaluate its performance on a variety of devices, fostering the intern's skills in developing efficient, open-source tools, with potential for contributing to academic publications.

Possible topics include:

  • Design and implementation of data structures for parallel external compression to achieve both speed-up and high compression rates (in Rust)


At least one of the following skills should be advanced and a good understanding of the other:

  • Rust Programming Language
  • Concurrent and Distributed Computing
Candidates should have good communication skills in English.

Host Researchers

Semi-automated Optimization Framework


Often, problem-solving involves taking two actions: model and solve. Typically, there is a tradeoff between ease of modeling and efficiency of solving. Therefore, one is often required to be a specialist to model and solve an optimization problem efficiently. We investigate the theoretical fundamentals and the implementation of tools to automize and make optimization frameworks. A general user should focus on the model of practical problems, regardless of the software or hardware available. Furthermore, we aim to encourage technical users to use our tools to improve their solving efficiency. The aim of this internship is to improve the fundamentals of this research and develop the proficiency of the intern in implementing efficient open-source tools. Furthermore, this research can result in academic publications.

Possible topics include:

  • Translation from native language to constraint programming through the use of a LLM or similar learning tools
  • Allocation of resources (software, hardware, threads, etc.) automatically for optimization problems, relying as much as possible on the JuMP.jl framework
  • Implementation of different solving strategies for a CBLS framework to help with research on CBLS solvers and general metaheuristics
  • Implementation of level-design tool for the Kumi Kumi Slope game using Constraint Programming


At least one of the following skills should be advanced and a good understanding of the other:

  • Julia Programming Language
  • Constraint Programming, Operational Research, Metaheuristics
Candidates should have good communication skills in English.

Host Researcher

Messages from Alumni

Arun Dunna (Year 2019)

I thoroughly enjoyed my time at IIJII, and the process was enjoyable from the initial application through the end of the internship. After I applied, I had an engaging video interview with some team members, and we discussed my prior work and potential projects at IIJII. Throughout the whole process, IIJII made it a point to ensure that I would be working on a project that I took interest in, which could be changed even upon arrival. Kitamura-san made the typical nightmare of logistics a breeze, and promptly answered any questions I had not just about the internship, but about life in Tokyo.

Upon arrival in Tokyo, I was greeted by the lab and given time to get acclimated to Japan. The lab's atmosphere was both welcoming and engaging, and everyone in the lab made regular efforts to discuss my project and provide input/guidance if needed. The locations of the office and provided housing were phenomenal, and Kitamura-san explained how to use the public transport to get around the city.

Daily life in Japan itself was great, and I highly recommend it to expand world viewpoints, which is another benefit to the internship. As an intern, I was required to be in the lab for a set time range each day, but a generous lunch slot was included and the lab provided a quiet yet collaborative space to work. My advisors (Romain and Zach) were at the lab nearly every moment that I was, and were hands-on throughout the whole internship, including regular meetings, online and in-person discussions, and collaborative brainstorming. All lab members were incredibly knowledgeable and were happy to answer any questions that I had, or to provide input when requested.

Overall, IIJII made a daunting internship in a foreign culture an enjoyable breeze. I made sustainable professional connections and produced quality research work as a part of their team. I highly recommend applying to the internship - it has been one of the best decisions of my academic career. I still continue to collaborate with the IIJII group even months after the internship on a number of projects.

Past Members

Year 2023

  • Vivian Band, University of Glasgow, Scotland
  • Deepak Gouda, Georgia Tech, U.S.A.
  • Jonathan Langlet, Queen Mary University of London, England
  • Arne Vogel, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany

Year 2019

  • Arun Dunna, University of Massachusetts, U.S.A.
  • Aniketh Girish, Amrita University、India
  • Christoff Visser, The University of Waikato, New Zealand
  • Talha Javed, National University of Science and Technology, Pakistan
  • Federico Mulas, University of Pisa, Italia
  • Bénoît Nougnanke, Universite Toulouse Paul Sabatier, France

Year 2018

  • Andreas Guillot, Strasbourg University, France
  • Francois Michel, Université catholique de Louvain, Belgium
  • Shinyoung Cho, Stonybrook University, U.S.A.

Year 2017

  • Cristina Georgiana Opriceana, Polytechnic University of Bucharest, Romania
  • Marc Anthony Warrior, Northwestern University, U.S.A.
  • Simone Ferlin, University of Oslo / Simula, Norway
  • Hoang Tran, Université catholique de Louvain, Belgium

Year 2016

  • Anant Shah, Colorado State University, U.S.A.
  • Argrios Tasiopoulos, University College London, United Kingdom
  • Julien Gamba, University of Strasbourg, France
  • Răzvan Certezeanu, Imperial College London, United Kingdom
  • Stefano Tracà, Massachusetts Insitute of Technology, U.S.A.

Year 2015

  • Alessandro Puccetti, University of Pisa, Italy
  • Daniel Gröber, Leopold-Franzens-Universität Innsbruck, Austria
  • Kenichi Takagiwa, Keio University, Japan
  • Lachlan Kang, The University of Adelaide, Australia
  • Mijung Kim, Stony Brook, Korea
  • Minoru Kanatsu, Osaka University, Japan

Year 2014

  • Daniele Iamartino, Politecnico di Milano, Italy
  • Gaëtan Briot, Université catholique de Louvain, Belgium
  • Tao Peng, University of Trento, Italy
  • Thomas Holterbach, University of Strasbourg, France

Year 2013

  • David Hauweele, Université de Mons, Belgium
  • Yaser Jararweh, Jordan University of Science and Technology, Jordan
  • Hyoyoung Lim, Nagoya University, Japan
  • Doudou Fall, Nara Institute Science and Technology, Japan

Year 2012

  • Andra Lutu, University Carlos III Madrid, Spain
  • David Lebrun, Université catholique de Louvain, Belgium
  • Hirokazu Hasegawa, Nagoya University, Japan
  • Julien Beaudaux, University of Strasbourg, France
  • Nam Dang, Tokyo Institute of Technology, Japan
  • Zachary Bischof, Northwestern University, U.S.A.

Frequently Asked Questions

General information

When will the application be open?

The summer internship application will be open at the beginning of December every year.

How long is the summer internship program?

The program is for 1~2 calendar months.

What are the start and end dates for the program?

Interns are able to select either from July 1st to August 31st or August 1st to September 30th. The actual visiting schedule will be discussed during the interview.

Can I extend the internship program?

No, this summer internship program is only for 2 months at longest.


Do I need to obtain a visa?

Yes, you will obtain a 3 month Designated Activities visa.

What are the required documents for obtaining visa?

Our admin staff will contact with you regarding the documents once the duration of your program is fixed.

What are the procedures for obtaining the visa?

IIJ will submit the required documents to Tokyo Immigration Office to obtain a certificate of eligibility for your visa.

When the certificate is issued, we will post it to you. After you receive the certificate, please go to the Japanese Embassy or consulate in your country to obtain the visa with your passport as soon as possible.

How long will it take the certificate of eligibility to be issued?

It will usually take about 1.5 to 2 months.


Where can I stay during the internship?

IIJ will provide a furnished apartment near the office for those who come from far places. Interns usually stay near Kanda Station in Tokyo. Please note that the accommodation is subject to change depending on the availability.

When can I get the detailed information regarding the accommodation?

IIJ will inform you of the details about 3 weeks before your arrival.

Flight ticket

Will IIJ pay for my flight?


When can I get the details of my flight?

IIJ will arrange the flight ticket after the certificate of eligibility is issued.

I would like to fly from France and fly back to US. Could IIJ provide the whole flight tickets?

No, we will provide a round trip ticket only.

Other information staying in Japan

Will travel insurance be provided by IIJ?

No, IIJ will not provide the insurance. You must make your own arrangements to join an overseas travel insurance plan which covers COVID-19 infection before you leave for Japan.

How can I receive my salary? Do you transfer to my overseas account?

IIJ will pay your salary in cash. The wire transfer is not accepted.

When is the pay day?

The pay day is on 25th every month, so you will need some money for day to day expenses until this date.

Do I need to wear formal clothes at IIJ?

No. The casual clothes are ok.

I don't speak Japanese. Can I survive in English?

Don't worry Tokyo and most tourist spots in Japan are usually "English-friendly".

Can I do some sightseeing after the internship is finished?

The visa is only for the internship, not sightseeing, therefore we would not recommend it. Still, it is: possible to arrange your return flight within a week after the last working day if you fix your itinerary beforehand. Note that IIJ cannot provide any support once your internship is over so that you need to take full responsibility for your extended stay. Also, you need to leave the apartment the day after the end of the program.

I have some additional questions about Summer Internship Program. Who can I contact?

Please contact at internship@iij.ad.jp.