JIJ
Senior Algorithm Engineer – Mathematical Optimisation
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Build the Algorithms Behind the Next Generation of Optimisation
At JIJ, we develop advanced computational technologies to solve complex decision-making problems across industry. Our flagship platform, JijZept, combines mathematical optimisation, advanced algorithms, AI, and emerging computing technologies to help organisations solve optimisation problems that are difficult to address with conventional approaches. We are now looking for a Senior Algorithm Engineer to join our UK, EU, and Japan team and contribute directly to the core optimisation technology behind JijZept.
This is not a role focused simply on using existing optimisation solvers. You will work on developing and improving the optimisation engine itself—designing algorithms, implementing them in production software, benchmarking their performance, and translating research ideas into technology used to solve real industrial problems.
What You’ll Do
As a Senior Algorithm Engineer, you will lead the research, development, and implementation of optimisation algorithms that improve the performance and capabilities of JijZept. Your work may include:
Core Algorithm Development
- Research and develop presolve techniques for real-world industrial optimisation problems, spanning linear, nonlinear, and combinatorial structures.
- Design and implement search algorithms, metaheuristics, and other optimisation methods.
- Investigate new algorithmic approaches to solve difficult, large-scale, and highly structured industrial optimisation problems.
- Improve solution quality, computational efficiency, scalability, and robustness of our optimisation technology.
Solver Engineering & Performance
- Contribute to the core solver and optimisation engine behind JijZept.
- Design and execute systematic benchmarks against leading optimisation approaches.
- Analyse algorithm performance and identify opportunities for architectural and algorithmic improvements.
- Translate mathematical and algorithmic concepts into robust, production-quality implementations.
Research to Product
- Evaluate academic research and emerging optimisation techniques.
- Prototype promising algorithms and assess their practical value.
- Translate successful research outcomes into production software.
- Work closely with software engineers and optimisation researchers to integrate new algorithms into JijZept and related products.
Industrial Problem Solving
- Work with our applied research and business teams to understand challenging optimisation problems from industrial customers.
- Identify where new algorithms or solver capabilities could materially improve performance.
- Develop reusable technologies rather than one-off solutions wherever possible.
Technical Leadership
- As a senior member of the team, you will also:
- Lead technical decisions within algorithm development projects.
- Review algorithm designs and implementations.
- Mentor and support other engineers and researchers.
- Contribute to the longer-term technical strategy and roadmap of JijZept.
- Depending on your interests, you may also have opportunities to explore emerging approaches in optimisation and computing, such as hybrid optimisation, quantum computing, and AI-based methods.
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Why Join JIJ?
This role offers a relatively rare opportunity to work on optimisation technology itself, rather than only applying existing commercial solvers. You will be able to:
- Develop algorithms that become part of a commercial optimisation platform.
- Work across mathematical research, algorithm design, software engineering, and production deployment.
- Test your algorithms against real large-scale industrial optimisation problems.
- See research ideas move rapidly from prototype to product.
- Collaborate with specialists in mathematical optimisation, AI, quantum computing, and software engineering.
- Work with industrial customers and research partners across Japan, the UK, Europe, and North America.
- Influence the technical direction of JijZept as JIJ expands internationally.
- We value both scientific rigour and engineering quality. The objective is not simply to develop interesting algorithms, but to build optimisation technologies that perform reliably on real problems.
Current Technical Focus
Our algorithm and optimisation work currently spans areas including:
- Mathematical programming
- Presolve techniques
- Nonlinear optimisation
- Combinatorial optimisation
- Metaheuristics
- Algorithm benchmarking
- Problem decomposition techniques
- AI-assisted optimisation
Our broader R&D activities also include collaborations with industrial customers, universities, national laboratories, and technology partners through projects in the UK, Europe, Japan, and North America.
Qualifications
We are looking for engineers and researchers with strong algorithmic foundations and the ability to turn mathematical ideas into high-quality software. You may be an excellent fit if you have:
- Strong programming skills in Python, C++, Rust, or similar languages.
- Strong knowledge of algorithms and data structures.
- Experience designing and implementing computational algorithms.
- Excellent mathematical, analytical, and logical problem-solving skills.
- Experience making technical decisions or leading technical projects.
- Ability to communicate complex technical ideas clearly in English.
- A background specifically in quantum computing is not required.
Preferred Qualifications
Experience in one or more of the following would be particularly valuable:
Optimisation & Algorithms
- Mathematical optimisation
- Operations Research
- Combinatorial optimisation
- Solver development
- Presolve techniques
- Search algorithms
- Metaheuristics
- Nonlinear optimisation
- Algorithm engineering and performance optimisation
Optimisation Software
- Experience with optimisation technologies such as: Gurobi, CPLEX, SCIP, HiGHS, Hexaly, OR-Tools
- Experience using these tools is valuable, but experience developing algorithms or solver technology itself is particularly relevant to this position.
Research & Engineering
- Academic or industrial research in optimisation, algorithms, or Operations Research.
- Scientific publications or conference presentations.
- Open-source software contributions.
- Benchmarking and computational experimentation.
- Production scientific software development.
- AI agent development.
- A Master’s degree or Ph.D. in Computer Science, Mathematics, Operations Research, Physics, Statistics, Engineering, or a related discipline is welcome, but equivalent industrial expertise is equally valued.
- We also welcome candidates whose strongest expertise is not explicitly listed above.
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Technology Environment
Our broader technology environment includes:
- Python
- C++ / Rust
- Google Cloud
- GitHub / GitHub Actions
- Docker / Kubernetes
- Slack / Notion
The exact technologies you work with will depend on the algorithm and product area.
Location & Working Arrangement
Location
- United Kingdom, EU, or Japan
Employment
- Full-time
Working Style
- JIJ operates a remote-first working environment.
- Most day-to-day work can be carried out remotely, with periodic travel to London for technical collaboration, workshops, customer engagements, and team meetings.
- We support flexible working hours and encourage a healthy work-life balance.
Visa Sponsorship
- Visa sponsorship and relocation support may be available for eligible candidates.
Compensation
- Typical annual base salary: £60,000–£90,000
- Compensation will be determined based on experience, technical expertise, and overall qualifications. Exceptional candidates may be considered above this range.
- Additional compensation and benefits may include:
- Stock options, where applicable
- Visa sponsorship if needed
Recruitment Process
Our typical hiring process includes:
- CV Review
- Initial Interview
- Technical Test
- Final Interview
- Offer
We aim to provide timely feedback and maintain a transparent recruitment process.
About JIJ
JIJ is a global deep-tech company specialising in mathematical optimisation, artificial intelligence, high-performance computing, and quantum computing. Our mission is: "Make Society Computable, Contributing to the Advancement of Humanity." Our flagship platform, JijZept, provides an integrated environment for modelling, optimisation, benchmarking, and deployment. JIJ works with industrial customers, research institutions, universities, and technology partners across Japan, the UK, Europe, and North America, applying advanced computational technologies to challenges in energy, manufacturing, logistics, telecommunications, healthcare, finance, infrastructure, and other industries.
Our Culture
We particularly value people who:
- Are genuinely curious about algorithms and optimisation.
- Enjoy breaking complex problems down into their fundamental structure.
- Want to translate advanced research into real-world technology.
- Balance mathematical rigour with practical engineering.
- Take ownership of technical decisions.
- Share knowledge and support other engineers.
- Communicate openly and collaborate across disciplines.
- Continuously learn and improve the technologies they build.
You do not need prior quantum computing experience to join JIJ. We provide opportunities to learn about quantum technologies after joining.
Equal Opportunity
JIJ is committed to creating an inclusive workplace where people with diverse backgrounds, experiences, and perspectives can thrive. We welcome applications from all qualified candidates regardless of race, ethnicity, nationality, gender, gender identity, sexual orientation, disability, age, religion, or any other protected characteristic.
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