Backend Engineer – API Integrationen, Connectoren, Worker/Jobs, Mailer Service, QA

JobgetherUnited KingdomPosted 2h agoonsite

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Backend Engineer – API Integrationen, Connectoren, Worker/Jobs, Mailer Service, QA based in United Kingdom.

This role is an opportunity to build robust backend systems and integrations that connect critical business platforms and services. You’ll work across APIs, connectors, background jobs, messaging, email delivery, persistence, and quality assurance. The position requires an engineering mindset focused on reliability, traceability, and handling real-world failure scenarios rather than relying on happy-path implementations. You’ll design integrations that remain resilient through rate limits, webhooks, timeouts, retries, and other operational challenges. Working on a project basis, you’ll have significant ownership over technical deliverables and architecture decisions. This is a strong fit for a backend engineer who enjoys solving complex integration problems and building dependable production systems.

Accountabilities

Build and maintain production-ready API integrations and connectors, prioritizing Box and HubSpot, followed by Microsoft Graph, Asana, and billing-related systems.
Implement reliable authentication and integration patterns using OAuth, webhooks, pagination, rate limits, retries, and robust error handling.
Design and develop queue-driven, stateful, and replayable workers and background jobs.
Build and maintain a mailer service supporting PDF attachments, structured logging, retry mechanisms, delivery checks, and deduplication/idempotency.
Design database schemas and implement clean, reliable migrations using PostgreSQL or comparable technologies.
Implement audit events and persistent traceability mechanisms, including correlation IDs and observability across distributed processes.
Develop comprehensive QA coverage, including contract tests, integration tests, and end-to-end regression testing for critical workflows such as document delivery and deadline-related processes.
Use Docker, queue/eventing technologies, and observability practices to support reliable deployment and operation of backend services.
Proactively identify failure modes and strengthen systems against timeouts, webhook failures, rate limiting, retries, duplicate events, and other production scenarios.

Requirements

Strong professional track record in backend engineering, with proficiency in Python, Node.js, Go, or a comparable backend technology.
Proven experience building and maintaining production API integrations, including OAuth, webhooks, pagination, rate limits, authentication, and error handling.
Solid understanding of relational databases, schema design, data persistence, and safe database migrations.
Strong testing mindset with experience implementing contract, integration, unit, and/or end-to-end tests.
Experience developing asynchronous, queue-based, or event-driven systems and background workers.
Understanding of reliability engineering principles, including idempotency, retries, replayability, deduplication, observability, and failure-mode analysis.
Experience working with Docker and modern backend development and deployment workflows.
Familiarity with PostgreSQL, queue/eventing systems, and application monitoring or observability tools.
Strong problem-solving skills and the ability to design systems that remain reliable outside of ideal or “happy path” scenarios.
Ability to work independently, take ownership of technical deliverables, and communicate clearly in a remote project environment.
Availability to work remotely, ideally aligned with Central European Time (CET) or European working hours.
Freelance or project-based experience is suitable for this engagement.

Benefits

100% remote working arrangement.
Flexible project-based engagement with workload agreed upon according to availability and project needs.
Full-time or part-time engagement options.
Freelance contract structure.
Opportunity to work on technically challenging API integrations, worker systems, messaging infrastructure, and QA automation.
Significant ownership over backend architecture, implementation, reliability, and delivery.
Opportunity to start as soon as possible.
Collaboration within an international and digitally focused professional environment.

How Jobgether works: We use an AI-powered matching process to ensure your application is reviewed quickly, objectively, and fairly against the role's core requirements. Our system identifies the top-fitting candidates, and this shortlist is then shared directly with the hiring company. The final decision and next steps (interviews, assessments) are managed by their internal team. We appreciate your interest and wish you the best! Why Apply Through Jobgether? Data Privacy Notice: By submitting your application, you acknowledge that Jobgether will process your personal data to evaluate your candidacy and share relevant information with the hiring employer. This processing is based on legitimate interest and pre-contractual measures under applicable data protection laws (including GDPR). You may exercise your rights (access, rectification, erasure, objection) at any time. #LI-CL1

Find more English Speaking Jobs in United Kingdom on Arbeitnow

Skills

Similar roles

Security Detection Engineer
eFinancialCareers·London, United Kingdom
Security Detection Engineer London (Hybrid) 600- 750 per day (Inside IR35) Initial 6-Month Contract We are looking for an experienced Security Detection Engineer to take ownership of detection engineering, and threat hunting across Azure and GCP environments. This is a hands-on opportunity for a security professional with strong SIEM, cloud security, and automation expertise who can operate independently in a…
- On-site
- Full-time
9m ago
KYC CLM AVP - Leading Bank
eFinancialCareers·London, United Kingdom
Our leading Banking client are looking for a talented and motivated individual to manage the end-to-end Rolling Review process within the Client Lifecycle Management division. You'll lead a team of KYC professionals, ensuring engagement with FO and offshore rolling review teams. Key responsibilities of the role: KYC end-to-end Oversight. Maintain close oversight of the end-to-end KYC process. Stakeholder management. Be…
- On-site
- Full-time
9m ago
Senior People Operations Coordinator
Teneo·Cardiff, United Kingdom
Location: hybrid, based at one of our UK offices: London, Cardiff, or Manchester.  <h2>The Role</h2> As a key member of the Global People Operations team, the UK People Operations Coordinator provides end-to-end operational HR support across a diverse UK portfolio. The role has primary employee-lifecycle ownership for Strategy & Communications, People Advisory and Corporate Functions, and coordinates onboarding and offboarding…
- On-site
- Full-time
2h ago
Senior People Operations Coordinator
Teneo·Manchester, United Kingdom
Location: hybrid, based at one of our UK offices: London, Cardiff, or Manchester.  <h2>The Role</h2> As a key member of the Global People Operations team, the UK People Operations Coordinator provides end-to-end operational HR support across a diverse UK portfolio. The role has primary employee-lifecycle ownership for Strategy & Communications, People Advisory and Corporate Functions, and coordinates onboarding and offboarding…
- On-site
- Full-time
2h ago
Backend Engineer II
Monzoreferrals·Cardiff, United Kingdom
📍London / UK Remote | 💰 <a href="https://monzo.com/documents/engineering-progression-framework-v4-0.pdf">Engineer II</a> £60,000 - £80,000 + <a href="https://monzo.com/careers/">Benefits</a> | <a href="https://monzo.com/blog/technology">Technology</a> - Engineering |   About our Engineering Teams: We have around 400 engineers across Monzo who design and build our in-house banking platform. We have big ambitions for the future, and technology plays…
- On-site
- Full-time
2h ago
Software Engineer - Triton
Graphcore·Bristol, United Kingdom
<h3 class="PDq2pG_selectionAnchorContainer" data-start="135" data-end="148">About the job</h3> Build the framework support that helps AI developers unlock Graphcore hardware. You will help Graphcore accelerators work seamlessly with state-of-the-art ML frameworks, including Triton and PyTorch. Reporting to a Team Lead in Frameworks, you will design, implement, optimise and support critical software. Your work will shape how researchers…
- On-site
- Full-time
2h ago
Senior Cloud Engineer
Graphcore·Bristol, United Kingdom
About the job Build the cloud platform that puts Graphcore AI systems into real use. As a Senior Cloud Engineer, you will develop and operate private cloud services for Graphcore teams and users. You will turn…
- On-site
- Full-time
2h ago
Principal Board Test Engineer
Graphcore·Bristol, United Kingdom
About the job Define how Graphcore tests complex hardware before it reaches production and the field. As Principal Board Test Engineer, you will lead advanced manufacturing test strategy for complex Circuit Card Assemblies. You will shape how Graphcore improves defect coverage, diagnostic resolution and production quality. Your work will influence products,…
- On-site
- Full-time
2h ago