Backend Software Engineer Junior-Mid Level - Programmatic

Location:  Hybrid – UK Contract Type: Permanent Hours: Full time Salary: Competitive COMPANY OVERVIEW MOBKOI is a fast-growing mobile company headquartered in London, with offices across central Europe, US and Asia. We use the latest in mobile ad technology to help premium brands effectively reach and engage with their clients' audiences.Bringing to market the most selective site list of premium global and local publishers enabling brands to be selective of where their ads are going to run and thus ensuring brand safety. MOBKOI prides itself on offering full transparency, bespoke creative builds and local market coordination. We are part of The Brandtech Group, formerly known as You & Mr Jones, working with partners developing the best technology across the globe.ROLE OVERVIEW As a Backend Software Engineer (Junior–Mid Level) – Programmatic, you will contribute to the development and evolution of MOBKOI’s programmatic advertising platform. You will work closely with experienced engineers on backend systems that power real-time bidding (RTB), campaign delivery, and large-scale integrations with SSPs and DSPs.This role is well suited to engineers early in their career who want to deepen their expertise in distributed systems, low-latency services, and cloud-based infrastructure, while gaining exposure to the programmatic advertising ecosystem. You will be supported through mentorship, code reviews, and progressive ownership of backend components.RESPONSIBILITIES•  Contribute to the development and improvement of MOBKOI’s programmatic backend systems, including components of the real-time bidding (RTB) pipeline.•  Support the design and implementation of scalable, reliable, and high-performance services handling large volumes of traffic.•  Work alongside senior engineers to help evolve system architecture while balancing performance, cost efficiency, and reliability.•  Assist in monitoring system performance and contribute to initiatives that optimise infrastructure usage and operational cost.•  Participate in diagnosing and resolving issues related to distributed systems, including latency, availability, and scaling challenges.•  Implement backend components following best practices in fault tolerance, load balancing, and resilient design.•  Develop an understanding of the programmatic advertising ecosystem, including SSPs, DSPs, bidding flows, and ad exchanges.•  Contribute to discussions around technology selection, tooling, and build-vs-buy  decisions.•  Collaborate with product, data, and business teams to ensure technical solutions align with business needs.•  Actively participate in code reviews, technical discussions, and continuous improvement initiatives.KEY SKILLS & COMPETENCIES•  Experience in backend software development, gained through a first professional role, internship, or apprenticeship.•  Solid engineering fundamentals with Go (or another backend language with a strong willingness to learn Go).•  Interest in or exposure to distributed systems and high-traffic environments.•  Understanding of core concepts around scalability, reliability, and high availability.•  Familiarity with cloud platforms such as AWS or GCP.•  Awareness of cost-efficient engineering practices and infrastructure optimisation.•  Curiosity about the programmatic advertising landscape and how technical systems support business outcomes.•  Strong collaboration skills and the ability to communicate clearly within a cross-functional team.BEHAVIOURS This role operates in a fast-moving, high-standards environment and requires someone who is motivated to learn, take ownership, and deliver quality work. The role holder is expected to manage their time effectively, adapt to change, and contribute positively to team and business outcomes.The role offers autonomy and is suited to someone who is comfortable balancing independent work with cross-functional collaboration.What we’re looking for:•  Motivation to contribute to the growth and success of the business•  A proactive, adaptable mindset with the ability to learn quickly•  Strong ownership and accountability for outcomes•  Clear and professional communication with a range of stakeholdersYou may also have experience in the following: Backend Software Engineer, Junior Backend Engineer, Mid-Level Backend Developer, Go Developer (Golang Engineer), Software Engineer – Backend, Programmatic Engineer, AdTech Engineer, RTB Engineer (Real-Time Bidding Engineer), Distributed Systems Engineer, Cloud Backend Engineer (AWS / GCP), Platform Engineer – AdTech, API Developer (Backend), High-Performance Systems Engineer, Programmatic Advertising Developer, Software Engineer – AdTechREF-226 991