Backend Engineer

Location: London, UK (based in London office, with in-person collaboration two days per week) Remote work allowance: False (requires 2 days/week in-office) Employment type: Full-time Experience level: Mid to Senior (4+ years professional experience required) Salary: Base Pay Range $170,000 - $185,000 USD (US target salary range for this full-time position)

Company Overview

Pelago is the world’s leading virtual clinic for Substance Use Management. The program provides guidance, support, and treatment for members seeking to overcome tobacco, alcohol, and opioid use. Pelago delivers personalized solutions based on individual health, habits, genetics, and goals. Services range from education to cognitive behavioral therapy (CBT) to comprehensive medication-assisted treatment (MAT). Pelago supports hundreds of employers and health plans and has helped over 750,000 members.

About Pelago Engineering

• Outcome-oriented problem solvers working closely with product, design, and clinical teams.
• Evolving development lifecycle with AI integration.
• Focus on system design, judgment, and impact rather than just implementation.

How We Work

• Outcome-driven: Success measured by learning, impact, outcomes.
• AI-native: Use AI across SDLC for implementation, testing, review.
• High autonomy & accountability: Ownership over domains with responsibility for quality and results.
• Cross-functional: Engineers partner with Product, Design, Data, Clinical teams.
• Quality & safety: Reliability and correctness are first-class concerns in a regulated domain.

What You’ll Do

• Own meaningful problem spaces end-to-end from discovery through delivery and iteration.
• Design and evolve systems supporting safe, scalable AI-augmented development.
• Use data and experimentation to validate solutions.
• Collaborate cross-functionally balancing member impact, clinical constraints, technical tradeoffs.
• Shape tools, processes, culture.

Role Overview

As a Backend Engineer you will:

• Build scalable, performant, secure APIs.
• Maintain/evolve serverless AWS architecture using Node.js and TypeScript.
• Contribute to event-driven system development; own core feature implementation/refactoring.
• Design/optimize MySQL databases including schema design and query performance improvements.
• Manage/integrate third-party APIs ensuring reliability/security/maintainability.
• Implement best practices for code quality/testing/deployment automation in agile environment.
• Partner cross-functionally translating business requirements into scalable technical solutions.

Requirements / What We're Looking For

• 4+ years professional backend engineering experience.
• Extensive experience with Node.js and TypeScript.
• Proven track record with event-driven architectures.
• Strong SQL skills: schema design, optimization, scaling.
• Strong AWS expertise: API Gateway, SNS, SQS, Lambda, Cognito, EC2, RDS, S3, CloudWatch, VPC.
• Experience integrating/managing third-party APIs in production.
• Curiosity about emerging technologies including AI; proactive mindset for innovation.
• Familiarity with testing frameworks; experience writing unit/integration tests.
• Based in London or within commuting distance (2 days/week in-office).

Nice to Haves:

• Experience with NoSQL databases.
• Infrastructure provisioning using Terraform.
• Experience scaling AWS environments in high-growth contexts.
• Knowledge of serverless architecture trade-offs/benefits.
• API security best practices.

Skills Summary

Programming Languages & Frameworks:

• Node.js
• TypeScript

Databases:

• MySQL (schema design & optimization)
• NoSQL (nice to have)

Cloud & Infrastructure:

• AWS services: API Gateway, SNS (Simple Notification Service), SQS (Simple Queue Service), Lambda functions,

Cognito (authentication), EC2 instances, RDS (Relational Database Service), S3 storage, CloudWatch monitoring, VPC networking

• Terraform (infrastructure provisioning - nice to have)

Architecture & Methodologies:

• Event-driven architecture
• Serverless architecture
• Agile development environment
• Testing frameworks: unit and integration testing

Tools & Practices:

• Code quality best practices
• Deployment automation

Soft Skills:

• Outcome ownership mindset
• Problem-solving starting from "why"
• Comfortable with ambiguity and collaborative problem-shaping
• Use of AI to amplify judgment and speed up work
• Systems thinking anticipating second-order effects
• Cross-functional collaboration

Benefits / What You'll Love About Us:

• Generous equity package
• Private Health Coverage
• Pension Plan
• Unlimited PTO Policy + Bank Holidays + “Me Time Days”
• Paid maternity/paternity/new parent leave
• Flexible working environment
• Annual Learning & Development stipend
• Wellness Reimbursement Program
• Access to Reproductive & Family Planning Care
• Substance Use Support for employees/family members

Additional Notes:

• Visa sponsorship not available for this position.
• Salary range reflects US target salary for full-time role as part of total compensation including bonuses and stock options.
• Pelago commits to equitable pay philosophy with compensation reviews twice yearly.