Assessing SRE skills
Interviews on system design and troubleshooting
Slide contents
1. Assessing SRE skills
Interviews on system design and troubleshooting
2. Alexander Polomodov
I lead digital ecosystem development at Tinkoff
I curate our System Design Interviews
And I interview for troubleshooting myself
3. From the hiring funnel to how to learn this
What we'll cover
The hiring process and why we check troubleshooting
What the candidate gets out of the section
How the section and a typical task look
Scoring, the contrast with design, and growth
4. 01. What SRE hiring looks like
Hiring stages and candidate levels
5. Troubleshooting sits inside the technical block
Hiring stages against the candidate's level
6. 02. Why we check this at all
From the company's side and the candidate's
7. Reliability is decentralised — the teams own it
Why we check troubleshooting skills
25M+ customers, and both they and the load grow
Many business lines, platforms and service lines
The products merge into an ecosystem
Engineers own the reliability of their own systems
8. An incident almost like the real one, at a low price
What the candidate gets out of it
Working an incident under near-real conditions
Normally only a production system gives that
Went brilliantly — likely a Senior/Lead offer
Went poorly — we say what to work on
9. 03. What the troubleshooting section looks like
Eight steps and a typical task
10. The candidate leads the incident investigation
What the troubleshooting section looks like
11. Two data centres share one database
What a typical task looks like
12. 04. How we score the candidate
Six axes and the level read off them
13. Six criteria form the candidate profile
The scoring criteria
14. 05. Troubleshooting and system design
How they differ and why one section remained
15. Restore a system or design one
How troubleshooting and system design differ
16. System design dropped: candidates averaged Junior
Ideally SRE = troubleshooting + system design
The ideal: fight fires and design systematically
The reality: design was passed at Junior level
So we stopped asking System Design
But we decided to teach it internally
17. 06. Wrap-up and how to get better
Theory and practice for both sections
18. Theory only works alongside practice
How to get better at system design and troubleshooting
19. The questions we covered
From the hiring process to how the two sections differ
What the hiring process looks like
Why we check troubleshooting skills
What the candidate gets out of it
What the section and a typical task look like
How we score, and how the sections differ
20. Links for further study
The sources from the talk's closing slide
An article based on this talk
Google SRE Book, SRE Workbook, a Mobile SRE Report review
«Release It!» and a repository of postmortems
My articles on the System Design Interview and preparing for it
21. Thank you!
polomodov.tech
All slides and links are in the Telegram channel
Alexander Polomodov, Technical Director & Fellow, T-Technologies
@book_cube