Freelance Software Engineer (Full Stack, React, TypeScript)

About Atmen

Atmen is a Munich-based RegTech startup revolutionising green certification. Our SaaS platform helps energy-intensive industries (fuels chemicals materials) automate compliance and certificationcutting down time by up to 90%.

We replace todays manual costly and unpredictable certification processes with continuous technology-driven verification. Our mission Making sustainable production simple scalable and cost-effective.
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About the Role**

Were looking for a Software Engineer to help build and deliver customer-facing solutions by integrating our core platform with a wide range of third-party systems and APIs. This role combines full-stack application development with systems integration requiring someone who enjoys solving complex technical challenges and turning customer requirements into reliable scalable software.

Youll work closely with product managers customer success and engineering teams to design develop and deploy solutions that connect our platform with our customers technology ecosystems.

Tasks

What Youll Do

• Design build and maintain full-stack applications using React TypeScript NestJS and PostgreSQL.
• Develop and maintain integrations with external APIs including REST and other web service technologies.
• Extend and customize our core platform to meet customer-specific business requirements.
• Design clean maintainable and scalable backend services and frontend applications.
• Collaborate with customers and internal stakeholders to understand integration requirements and translate them into technical solutions.
• Troubleshoot integration issues across distributed systems and work with third-party vendors when necessary.
• Write well-tested production-ready code with a focus on reliability performance and security.
• Participate in code reviews architecture discussions and continuous improvement initiatives.
• Contribute to documentation for integrations APIs and internal development processes.

Requirements

Must-haves

• Strong experience with TypeScript.
• Professional experience developing backend services with and NestJS.
• Experience building modern frontend applications with React.
• Solid understanding of PostgreSQL and relational database design.
• Experience consuming and integrating external APIs.
• Good understanding of RESTful API design and HTTP protocols.
• Experience with Git and collaborative software development practices.
• Strong problem-solving skills and the ability to work independently.
• Excellent communication skills and the ability to work directly with both technical and non-technical stakeholders.

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Nice-to-haves**

• Experience designing and building API integrations at scale.
• Familiarity with authentication standards such as OAuth 2.0 OpenID Connect JWT or SAML.
• Experience with cloud platforms (AWS or GCP).
• Knowledge of Docker and containerized deployments.
• Experience with CI/CD pipelines.
• Familiarity with event-driven architectures messaging systems or webhooks.
• Experience working in customer-facing or implementation engineering roles.
• Experience with AspenTech tools.

Job requirements

• Availability: Full-Time Freelancer
• Remote location preferably in the European Union
• Fluency in English

Benefits

How we work

• Asynchronous first: We minimise unnecessary meetings and document everything in Notion.
• Focus time & deep work: Meetings-free mornings 1 in-office Team Day per week.
• Fast-paced iterative development: We push to main frequently and release several times per week.
• Strong testing culture: Pragmatic test-driven development (TDD) heavy use of E2E tests.

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Why Join Us**

• Impact: Be part of a small high-performing team driving real-world sustainability impact.
• Hybrid work and central Munich offices: work from the office and from home.
• Growth: Join an early-stage startup with significant ownership and career growth potential.
• Cutting-edge tech: Work on exciting challenges in automation AI and compliance tech.

Meet the Team

Atmen was initially founded by Flore Quentin and Erika - forming a strong and competent team bringing 15 years of working experience in the renewable energy sector and an outstanding network. Their competencies are at the crossings between data analytics energy markets & regulation and product design.

What the team shares A huge drive to decarbonize our industry and a fundamental belief that a success is always a people success. An obsession to solve big problems and constantly raise the bar.

Atmen is an equal opportunity employer

We embrace diversity **and are committed to creating an inclusive environment for all employees and stakeholders. We are open to all candidates without regard to age color national origin religion gender or any other characteristics.

Employment Type : Freelance
Experience: years
Vacancy: 1