In my last 5 jobs:
- 3-7 devs to 1 tester(1 products);
- 4-10 devs to 1 tester(4 products);
- 20 devs to 1 tester (3-5 products in 3-7 projects);
- 2 devs to 1 tester (the tester doing PM, BA, Dev, etc… as well)
- 3 devs to 1 tester(main team 3 products - multiple subsystems); the tester is also working on 4 other products/teams/roles;
I do not have concerns on the ratio, the main problem is the difficulties of the context. Some of the past challenges:
- the higher the amount of managers messing up with things, the harder it is to track stakeholder needs and the goals can shift too quickly; imagine a product team of 4 having 6 managers and 7 stakeholders.
- the higher the amount of non-dev people that don’t actually do the work on the product, which are on the project, the more messier it is, as they’ll introduce extra complexity or need extra time to deal with;
- unrealistic development project release deadlines(where testing should be included); I’ve been at the same time in 7 projects, from 6 teams, having a deadline release in 2 weeks where I had to re-evaluate constantly actual dev time(estimate possible delays on releases) and jump on testing one or the other(a few times per day);
- the more external systems complexity, the harder it can get; working with external systems with constant updates and having to optimize and build new features on them means dealing in another way with a few more external dev teams and internal departments;
- some people on projects like meetings; whenever I was in meetings up to 50% of the time, it was messing me up - constant interruptions, different useless or very useful topics, time to work was decreased;
- sometimes test-managers appear in the picture and instead of supporting, they stay in the way, slowing you down, removing focus from what’s risky/important, wasting your time and confusing project managers with unrealistic things;
Our team is starting to think about resourcing for the next year, unsure how many developers they’re going to be hiring but I want to make sure I ask for the right amount of testers for whatever they say.
I’d ask, how well do you know your context? What are the risks on the product/project, concerns of stakeholders, what’s the speed of dev, releases expectations, processes, managers and stakeholders, complexity and dependencies on people or systems, etc…
The ratio can be 0 testers to 10 devs up to more testers than devs…
Also to note, not all testers are equal, have the same strengths, have the same speed/efficiency, cost the same. There could be cases where you could have a single tester to replace 3 others. There could be cases where the devs or business are enough for testing the product.