50 backend software engineer jobs found

Senior Software Engineer - Identity & Authentication (Backend) - Contractor About the Role In the European Client Identity team, we are building and operating Vanguard’s authentication and MFA platform used by hundreds of thousands of clients across the UK and Europe. This is a hands-on senior backend role focused on designing, building, deploying, and operating cloud-based identity services. You will work in a highly regulated environment where security, reliability, and operational discipline matter. You don’t need to be an identity expert on day one — but you do need strong backend fundamentals, cloud experience, and a responsible, methodical engineering mindset.   This is a contractor role, available for up to 12-months.   In this role you will Build and evolve backend services that support login, MFA , and client authentication Design and implement REST APIs using NestJS / TypeScript...

Senior Software Engineer - Identity & Authentication (Backend) - Contractor About the Role In the European Client Identity team, we are building and operating Vanguard’s authentication and MFA platform used by hundreds of thousands of clients across the UK and Europe. This is a hands-on senior backend role focused on designing, building, deploying, and operating cloud-based identity services. You will work in a highly regulated environment where security, reliability, and operational discipline matter. You don’t need to be an identity expert on day one — but you do need strong backend fundamentals, cloud experience, and a responsible, methodical engineering mindset.   This is a contractor role, available for up to 12-months.   In this role you will Build and evolve backend services that support login, MFA , and client authentication Design and implement REST APIs using NestJS / TypeScript...

hiring experienced Python Engineers to support a variety of high-impact research collaborations with leading AI labs. Freelancers will help improve AI systems through work extending coding benchmarks that reflect real-world development across diverse languages and domains. This is a unique opportunity to apply your engineering expertise toward shaping the next generation of intelligent systems. Key Responsibilities Develop and validate coding benchmarks in Python by curating issues, solutions, and test suites from real-world repositories Ensure benchmark tasks include comprehensive unit and integration tests for solution verification Maintain consistency and scalability of benchmark task distribution Provide structured feedback on solution quality and clarity Debug, optimize, and document benchmark code for reliability and reproducibility Ideal Qualifications 3–10 years of experience as a backend software engineer, ML engineer,...

hiring experienced Python Engineers to support a variety of high-impact research collaborations with leading AI labs. Freelancers will help improve AI systems through work extending coding benchmarks that reflect real-world development across diverse languages and domains. This is a unique opportunity to apply your engineering expertise toward shaping the next generation of intelligent systems. Key Responsibilities Develop and validate coding benchmarks in Python by curating issues, solutions, and test suites from real-world repositories Ensure benchmark tasks include comprehensive unit and integration tests for solution verification Maintain consistency and scalability of benchmark task distribution Provide structured feedback on solution quality and clarity Debug, optimize, and document benchmark code for reliability and reproducibility Ideal Qualifications 3–10 years of experience as a backend software engineer, ML engineer,...

hiring experienced Python Engineers to support a variety of high-impact research collaborations with leading AI labs. Freelancers will help improve AI systems through work extending coding benchmarks that reflect real-world development across diverse languages and domains. This is a unique opportunity to apply your engineering expertise toward shaping the next generation of intelligent systems. Key Responsibilities Develop and validate coding benchmarks in Python by curating issues, solutions, and test suites from real-world repositories Ensure benchmark tasks include comprehensive unit and integration tests for solution verification Maintain consistency and scalability of benchmark task distribution Provide structured feedback on solution quality and clarity Debug, optimize, and document benchmark code for reliability and reproducibility Ideal Qualifications 3–10 years of experience as a backend software engineer, ML engineer,...

We’re building the future of qualitative research.   We’ve already secured 6-figure pilot deals from Fortune 500 companies and supported by a leading US Qualitative Research company and an AI venture builder.   Modern teams move fast, but deep human insight is still slow, expensive, and locked behind heavyweight research cycles. As a result, most everyday decisions such as creative iteration, messaging, positioning are made with guesswork rather than real understanding.   Traditional focus groups can’t keep up.   Focus eliminates this bottleneck by making qualitative insight instant, always-on, and scalable, without losing the depth that makes it valuable.   We’re building an AI-native research platform to become the default qualitative research layer for modern organisations.   The Role   We’re hiring our a contracted engineer (initially 3 months): a senior,...

Joining a new project Ideally have worked on Financial Services Projects before (Payments would be great) Emphasis on Architecture over Development (Must have a solid Development Background) Must be comfortable sitting in client meetings and advising Start date ASAP Duration 3 months (Likely to extend) 3 days / week in person working (London) Immediate Interviews   The best bit about Red Badger is, of course, the team. We are really proud of our people; we support and learn a lot from each other; we work really hard but have fun doing it. We are a diverse group made up of 22 different nationalities, speaking 17 different languages.   Our 3 founders, Dave, Cain and Stu, who have considerable tech and consultancy experience and still own 100% of the company. We've been consistently profitable and have grown responsibly from the beginning.   We are based at Old Street in the heart of ʺtech cityʺ...

Mindera is looking for a Java Engineer with hands-on experience in OpenTelemetry (OTEL) to join our backend engineering team. You’ll play a key role in designing, building, and instrumenting high-performance Java services. Requirements Design, develop, and maintain scalable Java-based microservices and backend systems. Implement observability best practices using OpenTelemetry (OTEL) for tracing, metrics, and logging. Collaborate with platform and DevOps teams to integrate telemetry data with systems such as Grafana, Prometheus, Jaeger, or Tempo . Define and maintain instrumentation standards across Java applications to ensure consistency and performance visibility. Diagnose complex production issues through telemetry data and performance profiling. Contribute to architectural discussions on service design, distributed systems, and monitoring strategy. Write clean, efficient, and testable code following best practices in CI/CD and...

Must have skills: Demonstrable experience with Solidity. Strong understanding of blockchain security practices and potential vulnerabilities. Proficiency in Hardhat and Foundry. Experience with Solidity security testing tools like Slither, Mythril, Echidna Practical experience with scripting languages like Javascript or Typescript. Ability to craft unit, integration, fork, and invariant tests, ensuring code longevity. Demonstrable aptitude for best development practices, data structures, algorithms, and methodologies. Bachelor's degree in Computer Science, Engineering, or a related STEM discipline. Excellent debugging and troubleshooting skills. Strong written and verbal communication skills. Self-motivated with the ability to work in a fast-paced, evolving environment. Proficient communication skills in English. Development background in sectors such as banking, finance, or trading, paired with a comprehensive grasp of financial instruments and systems. Bonus...

Back End Engineer (Python & GCP) Delivering scalable data infrastructure that transforms manual financial and actuarial processes into automated, auditable workflows. To deliver robust, scalable backend systems and data infrastructure that power automated data pipelines and dashboards for our global life reinsurance client in Bermuda. Hands On Experience: Building production Python applications with strong software engineering practices Designing and implementing distributed, large-scale systems Architecting solutions from scratch across the full development lifecycle Working with event-driven architectures and data pipelines Requirements Must Have: Exstensive production experience with Python including modern frameworks, testing, and deployment practices Proven experience designing and building distributed systems at scale Strong system architecture skills with ability to translate requirements into technical designs Familiarity...

Contract Remote Role Description As an hourly paid, fully remote Rust Engineer for AI Data Training, you will review AI-generated Rust code and explanations or generate your own, evaluate the reasoning quality and step-by-step problem-solving, and provide expert feedback that helps models produce answers that are accurate, logical, and clearly explained. You will assess solutions for correctness, safety, and adherence to the prompt; identify errors in ownership, borrowing, lifetimes, or algorithmic reasoning; fact-check information; write high-quality explanations and model solutions that demonstrate idiomatic Rust patterns; and rate and compare multiple AI responses based on correctness and reasoning quality. This role is with, a fast-growing AI Data Services company and subsidiary of that provides AI training data for many of the world’s largest AI companies and foundation model labs. Your work will directly help improve the world’s premier AI models...

Back End Engineer (Python & Azure) Delivering scalable data infrastructure that transforms manual financial and actuarial processes into automated, auditable workflows. To deliver robust, scalable backend systems and data infrastructure that power automated data pipelines and dashboards for financial services clients.   Requirements Hands On Experience:   Designing and implementing distributed, large-scale systems Architecting solutions from scratch across the full development lifecycle Working with event-driven architectures and data pipelines Building production Python applications with strong software engineering practices   Must Have:   Extensive production experience with Python including modern frameworks, testing, and deployment practices Proven experience designing and building distributed systems at scale Strong system architecture skills with ability to translate requirements into...

Back End Engineer (Python & Azure) Delivering scalable data infrastructure that transforms manual financial and actuarial processes into automated, auditable workflows. To deliver robust, scalable backend systems and data infrastructure that power automated data pipelines and dashboards for financial services clients. Requirements Hands On Experience: Designing and implementing distributed, large-scale systems Architecting solutions from scratch across the full development lifecycle Working with event-driven architectures and data pipelines Building production Python applications with strong software engineering practices Must Have: Extensive production experience with Python including modern frameworks, testing, and deployment practices Proven experience designing and building distributed systems at scale Strong system architecture skills with ability to translate requirements into technical designs Familiarity with...

Required Core Skills: AWS Cloud services with Python, AWS Lambda, DynamoDB, RDS, AppSync, RESTful APIs 1. AWS Cloud services with Python and its frameworks such as Django on the backend 2. Cloud - AWS such as Lambda, DynamoDB, RDS, AppSync. 3. Experience working with RESTful APIs and/or GraphQl 4.Good understanding of development best practices such as pair programming, TDD 5. Work in an agile Minimum years of experience: 8 to 10 Years Job Type: Freelance Pay: £300.00-£350.00 per day  

We are seeking a passionate Software Engineering Manager who will provide technical expertise and operate with excellence. Being creative, curious, and confident, you will be an integral part of our empowered, self-managing, multi-disciplinary engineering teams - designing, building, releasing, and maintaining products. You will play a key role in driving our ambition to create a best-in-class software engineering team, environment, and culture. This is an initial 6 month contract (outside IR35) that requires you to work on client site 3 days a week in London, Paddington. Requirements   Your key accountabilities will include: Team Management: Build, mentor, and manage a high-performing software engineering team. Foster a culture of collaboration, innovation, and continuous improvement within the team. Facilitate communication and collaboration among team members. Ensure budgets, people and resource allocation, and workload, balance across...

Freelance Senior Software Engineer - £day rate (outside IR35) Joining an enterprise project in production phase Project is integration multiple 3rd party services into a financial services platform.  Looking for front end (React Native) or Back end (.net) experience (Or both) Start date ASAP Duration 3 months (Likely to extend) 2 days / week in person working (London) Joining a cross functional team of 12 Immediate Interviews   The best bit about Red Badger is, of course, the team. We are really proud of our people; we support and learn a lot from each other; we work really hard but have fun doing it. We are a diverse group made up of 22 different nationalities, speaking 17 different languages.   Our 3 founders, Dave, Cain and Stu, who have considerable tech and consultancy experience and still own 100% of the company. We’ve been consistently profitable and have grown responsibly from the...

Mindera is looking for a Java Engineer with hands-on experience in OpenTelemetry (OTEL) to join our backend engineering team. You’ll play a key role in designing, building, and instrumenting high-performance Java services. Requirements Design, develop, and maintain scalable Java-based microservices and backend systems. Implement observability best practices using OpenTelemetry (OTEL) for tracing, metrics, and logging. Collaborate with platform and DevOps teams to integrate telemetry data with systems such as Grafana, Prometheus, Jaeger, or Tempo . Define and maintain instrumentation standards across Java applications to ensure consistency and performance visibility. Diagnose complex production issues through telemetry data and performance profiling. Contribute to architectural discussions on service design, distributed systems, and monitoring strategy. Write clean, efficient, and testable code following best practices in CI/CD and...

Mid Back End Engineer (Python & GCP) Delivering scalable data infrastructure that transforms manual financial and actuarial processes into automated, auditable workflows. To deliver robust, scalable backend systems and data infrastructure that power automated data pipelines and dashboards for our global life reinsurance client in Bermuda. Hands On Experience: Building production Python applications with strong software engineering practices Designing and implementing distributed, large-scale systems Architecting solutions from scratch across the full development lifecycle Working with event-driven architectures and data pipelines Requirements Must Have: 4+ years production experience with Python including modern frameworks, testing, and deployment practices Proven experience designing and building distributed systems at scale Strong system architecture skills with ability to translate requirements into technical designs Familiarity...

Contract Remote Role Description As an hourly paid, fully remote Rust Engineer for AI Data Training, you will review AI-generated Rust code and explanations or generate your own, evaluate the reasoning quality and step-by-step problem-solving, and provide expert feedback that helps models produce answers that are accurate, logical, and clearly explained. You will assess solutions for correctness, safety, and adherence to the prompt; identify errors in ownership, borrowing, lifetimes, or algorithmic reasoning; fact-check information; write high-quality explanations and model solutions that demonstrate idiomatic Rust patterns; and rate and compare multiple AI responses based on correctness and reasoning quality. This role is with, a fast-growing AI Data Services company and subsidiary of that provides AI training data for many of the world’s largest AI companies and foundation model labs. Your work will directly help improve the world’s premier AI models...

We are looking for a Principal Software Engineer in Test to lead and evolve our quality engineering practice across backend services and client applications. This role is hands-on, highly technical, and focused on building robust, scalable test automation for REST and WebSocket APIs, as well as web, mobile, and desktop client UIs. As a principal-level engineer, you will define testing strategy, design automation frameworks, and partner closely with backend, frontend, mobile, and platform teams to ensure quality is built into the system. This is not a manual QA role.   Employment Type This is a full-time independent contractor position. We are not currently hiring for direct employee positions. Location This is a fully remote position. Work where you perform your best.   Key Responsibilities Own the end-to-end test automation strategy, architecture, and integration across backend services and client applications Design,...