Senior Software Engineer, Sandboxes (London or East Coast Preferred)

Senior Software Engineer, Sandboxes (London or East Coast Preferred)

London Full-Time 80100 - 97900 £ / year (est.) Working from home possible
Docker

At a Glance

  • Tasks: Design and develop secure runtime environments for AI coding agents.
  • Company: Join Docker, a leading brand in developer tooling with a remote-first culture.
  • Benefits: Enjoy flexible work, generous PTO, tech stipends, and equity options.
  • Other info: Collaborate with a diverse team and grow your career in a dynamic environment.
  • Why this job: Make a real impact on the future of software development with cutting-edge technology.
  • Qualifications: 8+ years in software engineering with strong leadership and communication skills.

The predicted salary is between 80100 - 97900 £ per year.

About Docker

Docker has been one of the most loved brands in developer tooling, trusted by more than 20 million monthly users and over 20 billion container image pulls. From solo founders to the world's largest companies, developers rely on Docker to build, share, and run their applications across our suite of products including Docker Desktop, Docker Hub, and Docker Scout.

We are a globally distributed, remote-first team building the tools that define how software gets built and delivered. As AI agents redefine software development, Docker is at the center of that shift, providing the sandboxed environments, verified images, and secure infrastructure that make autonomous workflows trustworthy by default.

The Docker Sandboxes team is building the runtime that lets AI coding agents run safely on a developer's machine: disposable, isolated microVM sandboxes that each get their own Docker daemon, filesystem, and network. This is the core of Docker's sbx product: developers can give an agent the autonomy it needs to get real work done without it ever touching the host, and tear the whole environment down when it's finished.

The successful candidate is a technical, product-minded engineer with deep experience building secure, isolated runtime environments (sandboxes, containers, or VMs) and a track record of shipping and owning that kind of infrastructure in production at scale. They think naturally about isolation and security boundaries, understand the tradeoffs involved in running untrusted or semi-trusted workloads safely, and can reason confidently about a system that spans multiple surface areas.

They can drive clarity and consensus on hard, ambiguous problems that cross team and component boundaries, raise the bar for engineering quality wherever they work, thrive in a remote-first environment, communicate clearly across time zones, work with our users, while bringing curiosity and craftsmanship to hard problems.

Please note: this role is currently prioritising candidates currently located in the Eastern time zone (US or Canada), or in the EU.

Responsibilities

  • Design, develop, and lead improvements to the sandboxes product across agent integration, tool permissions, and developer-facing workflows.
  • Investigate and resolve correctness, performance, and stability issues in the agent integration layer across macOS, Windows, and Linux.
  • Drive the reliability and performance of sandbox creation, session management, and teardown for AI agent workloads.
  • Collaborate with peers, Product, and adjacent teams to evolve the architecture as requirements grow.
  • Mentor engineers on the team and set the bar in design reviews and code reviews.
  • Engage with the open source and agentic development community around sandboxing, MCP, and related ecosystems.
  • Participate in on-call rotations and respond to critical stability issues affecting users.
  • Document your work clearly and share knowledge with the rest of the team.

Qualifications

  • 8+ years of software engineering experience, with demonstrated technical leadership on production systems at scale.
  • Bachelor’s degree in Computer Science, Engineering, or a related field, or equivalent practical experience.
  • Experience building developer tools, desktop applications, or runtime infrastructure used directly by developers.
  • Familiarity with the agentic software development ecosystem: how coding agents work and how tools like Claude Code, Codex, or similar agents interact with their environment.
  • Ability to reason about isolation and security boundaries: what a sandbox should and shouldn't expose, and how to make safe defaults obvious to users.
  • Experience driving architecture and technical strategy across multiple engineers or teams.
  • Strong written and verbal communication skills.
  • Comfortable working with a high degree of autonomy in a remote-first environment.

What to Expect

  • First 30 Days
    • Build an understanding of our codebase.
    • Meet the people on your team and those adjacent to it.
    • Build an understanding of the products we are shipping and our near-term technical priorities.
    • Deliver small fixes or improvements.
  • First 90 Days
    • Lead the design and development of a significant improvement or feature of the local sandboxes stack.
    • Engage with our open source project and the relevant upstream communities.
    • Shape the team's technical direction, and drive architecture discussions.
  • One Year Outlook (First Year)
    • Deliver measurable improvements to the correctness and performance of sandboxes.
    • Become a recognised technical owner of key parts of the codebase and a go-to technical leader for the local runtime.
    • Help us define the longer-term technical strategy for the filesystem layer in a way that fits with Product and Business goals, and rally the team behind it.

Docker considers visa sponsorship on a case-by-case basis based on business needs.

Compensation & Equity

United States: $160,900 – $260,700 + equity

Perks & Benefits

  • Remote-first by design – Work from your home, with offices in Seattle and Paris for connection and collaboration.
  • Flexibility that fits your life – We trust you to manage your schedule while delivering great work.
  • Time to recharge – Generous PTO, designated quarterly Whaleness Days, and a designated end-of-year Whaleness break.
  • Home office support – Set up your workspace for comfort and success.
  • Technology stipend – Equivalent to US$100 net per month to help support your work.
  • Learning & development – Annual stipend for conferences, courses, certifications, and continued learning.
  • Parental leave – 16 weeks of paid parental leave after six months of employment.
  • Equity for all full-time employees – Share in Docker's long-term success as we continue to grow.
  • Comprehensive benefits – Medical, retirement, and paid holidays vary by country.
  • Docker swag – Because representing the whale never gets old.

Docker is proud to be an equal opportunity employer. We are committed to building a team that reflects a broad range of backgrounds, experiences, and perspectives. We believe diverse teams build better products, make better decisions, and better serve our global community.

Senior Software Engineer, Sandboxes (London or East Coast Preferred) employer: Docker

Docker is an exceptional employer that champions a remote-first culture, allowing you to balance work and life while contributing to innovative app development. With a strong emphasis on employee growth through mentorship, training stipends, and a commitment to diversity, Docker fosters an inclusive environment where your contributions directly impact millions of users worldwide. Enjoy unique perks like quarterly Whaleness Days, a technology stipend, and equity in a rapidly growing start-up, making it a rewarding place to advance your career.

Docker

Contact Details:

Docker Recruitment Team

StudySmarter Expert Advice🤫

We think this is how you could land Senior Software Engineer, Sandboxes (London or East Coast Preferred)

Join Local Tech Meetups

Get out there and mingle with fellow developers by joining local tech meetups. It’s a fantastic way to meet people who might be working at Docker or know someone who does. Plus, you can pick up some trendy tech skills and trends while you're at it!

Contribute to Open Source Projects

Show off your coding chops by jumping into open-source projects. Not only does this give you practical experience, but it also gets you noticed in the dev community. You'll create a killer portfolio that speaks volumes about your skills to Docker.

Tap into Online Developer Communities

Don’t underestimate the power of online developer communities like GitHub, Stack Overflow, and even Reddit. Participate in discussions, share your projects, and build your visibility. We can often find opportunities through these channels that can lead to a full-time gig at companies like Docker.

Explore Job Boards Specifically for Tech Roles

Keep your eyes peeled on job boards that focus on tech roles. Sites like TechCareers or Stack Overflow Jobs can often have listings for companies like Docker that might not show up on broader job sites. Make it a habit to check these regularly, and don’t hesitate to apply directly through our website!

We think you need these skills to ace Senior Software Engineer, Sandboxes (London or East Coast Preferred)

Software Engineering
Technical Leadership
Runtime Infrastructure Development
Sandboxing
Containerisation
Security Boundaries Reasoning
Performance Optimisation

Some tips for your application 🫡

Show off your coding skills:When applying for a software engineering role, it's super important to showcase your coding skills. Make sure your CV includes your tech stack, any relevant programming languages you’re comfortable with, and examples of projects you've worked on. If you have a GitHub profile, link it up! We love to see code in action.

Tailor your portfolio:For a full-time role, we’d expect to see some solid examples of your work in your portfolio. Make sure to include at least two or three projects that highlight your problem-solving skills and your ability to work with different technologies. Focus on the projects that are most relevant to the position at Docker.

Craft a killer cover letter:Your cover letter is your chance to stand out—make it personal! Explain why you want to work at Docker and how your skills align with the role. Show us your passion for software development. We dig enthusiastic candidates who understand the value of collaboration and continuous learning!

Be clear and concise:When it comes to writing your CV and cover letter, clarity is key. Avoid jargon that could confuse us and stick to simple, direct language. Highlight your achievements with quantifiable results where possible, and keep everything easy to read. A well-organised application goes a long way!

How to prepare for a job interview at Docker

Brush Up on Your Coding Skills

For a full-time software engineering role, it's crucial that we stay sharp with our coding abilities. Expect technical questions that might involve solving problems on the spot or discussing algorithms. Practise on platforms like LeetCode or HackerRank to get comfortable with the types of questions that often come up.

Know Your Tools and Frameworks

Make sure we’re well-acquainted with the tools and technologies listed in the job description. Familiarise ourselves with any specific frameworks or programming languages mentioned. If Docker uses React or Node.js, for instance, be ready to discuss how we’ve used them in previous projects or coursework.

Showcase Your Projects

Bring along a portfolio that highlights our best work. This could be code samples, GitHub repositories, or any side projects we’ve built. Make sure we can talk through our thought process for each project, especially the challenges we faced and how we solved them—this shows our problem-solving skills in action.

Prepare for Behavioural Questions

While technical skills are key, full-time positions also require cultural fit. Be ready to discuss our previous experiences and how we handle teamwork, conflict, and deadlines. Brush up on the STAR method—Situation, Task, Action, Result—to clearly articulate our past experiences when discussing how we've contributed to a team.