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Senior JavaScript developer

This is Undefined|Bow Road, E3 4LW
16 days ago

Our Story

Undefined is a small London-based product studio. We work with startups across a range of different sectors. All ideas are different and we treat them that way. We love creating digital products with a purpose and we are looking for a like minded and passionate developer to join our team and help us continue to meet our goals.

About the role

We are looking for a Mid to Senior JavaScript developer with solid experience in building clean and well-coded web applications. We are a small team and so independence and confidence in your coding is key. You won't have anyone looking over your shoulder and we strongly believe in self accountability to get the job done.

The ideal candidate will be a great solo worker who can roll their sleeves up and get their head down, but someone who is also a great communicator, who can feedback to the rest of the team on their progress, blockers, and stick to a timeline. In addition to someone experienced in JavaScript and JS frameworks (particularly React), time management skills and working on prioritised tasks is essential.

Your tasks will be extremely varied as you will be working on a range of products and projects for different, exciting clients throughout the year, rather than iterating on one main project over time. This is an exciting opportunity to make a big impact within an innovative, supportive and growing agency that would love to add another skilled JS dev to its ranks.


  1. Frontend development with React and JavaScript

  2. Develop flexible, varying sized websites and mobile apps (using tech like Firebase, React, Gatsby, Next)

  3. Assist with scoping and planning of projects

  4. Assist other team members in developing needed features

  5. Take a user-centered approach and rapidly test and iterate

  6. Potential to be involved on the design side (not required)

What We're Looking For

  1. 4+ years experience in frontend development of web/app projects

  2. Extensive experience (2+ years) with React and Javascript

  3. Experience integrating API's & Auth workflows

  4. A positive working attitude (and excellent at working for stretches of time without close supervision)

  5. Proven track record of learning new technologies and tools on your own initiative (we want to see your side projects!)

  6. Ability to understand the needs of the client, question business logic behind features and ensure our client's needs are being met

Nice To Have

  1. Production experience with Firebase

  2. Experience in working with Shopify

  3. Strong UI/UX understanding and creative mindset

  4. Ability to conduct User Testing and QA testing


  1. A friendly, vibrant, and ambitious team

  2. A competitive salary

  3. Cool office in London

  4. Flexible working (some remote considered - negotiable)

  5. Regular (online and offline) get-togethers