Senior Web Services Engineer

Salt Digital Recruitment; Greater London; Remote; GBP 125,000 - 150,000; Full time

Job summary

A leading recruitment agency is seeking a Senior Web Services Engineer for a contract role. This fully remote position requires experience in backend API development and a proven track record of building complex integrations. Ideal candidates will thrive in fast-paced environments and possess strong system design skills. Immediate start available.

Qualifications

• 5+ years of backend API development experience.
• Proven experience building APIs for enterprise-grade apps.
• Strong skills in system design and SQL data modeling for high-traffic applications.

Responsibilities

• Design and implement scalable database schemas and API interfaces.
• Architect clean, performant RESTful APIs and GraphQL solutions.
• Drive end-to-end project delivery from requirements to development.

Skills

Backend API development experience

Python/Django

Node.js/NestJS

Golang/Gin

System design and SQL data modeling

Experience with LLM/AI features

Excellent communication skills

Job description

Contract Senior Web Services Engineer

3-6 Month Contract

Hourly Rate in USD – Negotiable

Fully Remote – Open to candidates worldwide

We are seeking a Senior Web Services Engineer to join on a contract basis, working remotely with a globally distributed team. This role is ideal for someone who thrives in ambiguity, enjoys problem-solving, and can design scalable, high-performing systems that integrate legacy platforms with modern web services.

Key Responsibilities

• Design and implement scalable database schemas and API interfaces to support large-scale user-generated content with a focus on security, performance, and developer experience.
• Architect clean, performant RESTful APIs, GraphQL solutions, and AI-powered features integrating platforms such as Stripe, Shopify, Salesforce, and OpenAI.
• Build and integrate Customer Data Platforms (CDPs) and AI/ML capabilities (semantic search, RAG, vector embeddings, prompt engineering).
• Drive end-to-end project delivery – from scoping requirements to hands-on development in Python, Node.js, Go (with some PHP).
• Troubleshoot third-party integrations, resolve performance bottlenecks, and develop automated tests.
• Collaborate with cross-functional teams across multiple time zones, translating complex business requirements into clear, actionable solutions.

Skills & Experience

• 5+ years’ backend API development experience with Python/Django, Node.js/NestJS, or Golang/Gin.
• Proven experience building APIs for enterprise-grade apps with complex integrations.
• Strong skills in system design and SQL data modeling for high-traffic applications (10k+ daily users).
• Hands-on experience with LLM/AI features (semantic search, vector DBs, RAG, prompt engineering).
• Comfortable working in fast-paced, agile environments and collaborating with global teams.
• Excellent communication skills with the ability to explain technical trade-offs to non-technical stakeholders.

Rates depend on experience and client requirements

Job Information

• Job Reference: JO-2509-356235
• Salary: Hourly
• Job Start Date: ASAP
• Job Industries: Software Engineering
• Job Locations: Greater London
• Job Types: Contract