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Ask HN: Language-agnostic concepts a Backend Engineer should know?

• ianpurton 5y ago
  Some that spring to mind - Database Migrations - Kubernetes - Basic RPC and code generation i.e. gRPC, OpenAPI and GraphQL. - Realtime Concepts, i.e. Kafka, MQTT - DevSecOps - Builds. i.e. make files. - Jobs, i.e. cron or batch and job workflows. - Offsite incremental DB backups and restore. - Infrastructure as Code i.e. Pulumi.
• dudul 5y ago
  Isn't an ORM the perfect example of something that is not language agnostic?
  • onei 5y ago
    The implementation is, but the concept is transferable. Pretty much the same for most concepts in programming.
    • exdsq 5y ago
      SQL is far more useful to learn than any one ORM or even the general concept of am ORM.
    • loevborg 5y ago
      ORMs are language-specific, but the insight to avoid ORMs for the rest of your life because of impedance mismatch is general and deep.
• etaham 5y ago
  Distributed systems, consensus & data consistency concepts
• eatonphil 5y ago
  How to set up a decently secure, monitored and backed up server.
• eterps 5y ago
  Domain Modeling (check out the book 'Domain Modeling Made Functional').
• throwaway019254 5y ago
  Idempotence
• tekstar 5y ago
  C and how to debug it. If you understand the system a layer of abstraction or two below the layer you work in, you will be able to debug deeper. Learn system calls, Various ways how to examine processes. I learnt a lot of this back in the day by completing war games on a site called digital evolution (dievo). Those are antiquated now but still a really fun way to learn it.
  • tifadg1 5y ago
    sounds very niche from an employability PoV.
    • sidlls 5y ago
      These skills have helped me at every single job I've had, including my current one, where I've employed the skill a couple of times to discover bugs or unintended side-effects in third-party library code. For context I've worked in the industry for about 15 years now, in roles ranging from low-level programming on real-time systems to (currently) high level machine learning work. It might be niche, but it can also be a differentiator--even if I'm not the fastest coder or the best architect I have these other skills that make me valuable at critical times. That's worth something anywhere. And it's not even knowledge of C or C++, or syscalls or whatever: it's just basic "use a debugger" (not merely pantomime the commands, but understand what's going on) skills that can be the real game changer.
      • SOLAR_FIELDS 5y ago
        Totally agree with this. I have never written C or C++ in a professional manner but just knowing how to debug and compile it has proved to be an invaluable skill. Lots of software ecosystems often have some underlying C/C++ code that they are calling out to and being able to dive into that when there is an issue is an incredible skill to have. Make, Ninja etc. are fairly straightforward compared to something like Gradle and just knowing my way around that and Clang/GnuCC has gotten me a lot farther in my career.
    • fennecfoxen 5y ago
• Oleg2tor 5y ago
  REST
• throwaway81523 5y ago
  Security mindset: read the book Security Engineering (it is online), less for specific technical info than for the many war stories etc. which will help you guard against vulnerabilities and unforeseen consequences. Basics of cryptography: there are many dumb errors to avoid. Antirez's general advice about "10x programmers" is good: http://antirez.com/news/112 http://antirez.com/news/112 Thorough (not just basic) knowledge of SQL, if you don't count that as a language. The sqlite.org "technical and design documents" about sqlite's virtual machine and its query planner are well worth reading, and apply to other databases as well. ORM's are less important than SQL, and are usually language specific as someone mentioned. Reasonable clue about socket programming, even if you're doing everything with libraries that wrap the details. Comfort using debugging and profiling tools. Lots of other stuff, I'm sure.
  • comprev 5y ago
    This book? https://www.cl.cam.ac.uk/~rja14/book.html https://www.cl.cam.ac.uk/~rja14/book.html
    • throwaway81523 5y ago
      Yes. It is a little bit old by now, but it is a great book.
    • throwaway81523 5y ago
      Added: Oh nice, there is a third edition (2020) now. I only knew about the 1st and 2nd editions. The 2nd ed is completely online but the 3rd only has sample chapters online: OTOH, the 3rd is in all likelihood an updated/expanded version of the 2nd. So you could read the 2nd and decide about buying the 3rd. I'd say it's a book for inspirational bedtime reading, rather than careful study or reference. But it's great in that way. Security is about mindset more than anything else, and the book puts you right into it.
• comprev 5y ago
  - How to write clean and concise documentation, including references to further reading material which helped you solve that particular problem. - Basics of server/runtime environment security (RBAC, least privileges, common threats, etc.)
• danpalmer 5y ago
  I think it's important to know about different data storage options and their trade-offs. Managing state is one of the hardest parts of backend development, particularly at scale, so an understanding of the trade-offs in databases/caches/blob-storage/queues, and when each is useful is important. I'd pay close attention to speed and "correctness". What's the consistency model of a system? Can we lose data and if so how? What's the throughput? Latency? These help choose good technology for backend systems, and helps answer questions like: - Can we do this in-band while serving a user request? - Can we do it 100 times to serve a request? - If it completes successfully can we trust it or do we still need to handle failure? - Can we trust it immediately or eventually? There are lots of technologies and terms for all of this but I've specifically avoided them because the important bit is the mental model of how these things fit together and the things they allow/prevent.
  • SOLAR_FIELDS 5y ago
    Absolutely this. Also, I’ve had to explain this to so many other engineers, both junior and senior to me: most data is inherently relational. This next statement is a bit opinionated: 9 times out of 10 you probably want an RDBMS. I’ve seen so many attempts to shoehorn some ElasticSearch/Mongo/Neo4j/whatever database into a design because the developer wanted to work on CoolDatabaseTech. Then you’re stuck dealing with joins in CoolDatabase that it wasn’t really designed to do and frustrated at CoolDatabase’s lack of drivers in X language. Later on you’re dealing with stability and scalability issues you would never see with BattleTestedRDBMS. The amount of capability a well designed Postgres instance can output is insane. I’ve seen a single vertically scaled Postgres instance compete with 100+ node Spark clusters on computations.
    • danpalmer 5y ago
      Exactly, but it goes a lot further than RDBMSs. For example does the application expect that all items on a queue will be processed? If so then you need a durable queue and Redis probably isn't a good idea, and this will likely reduce the throughput of the queue which might change how it needs to be used. One I've been bitten by several times is expecting APIs to allow me to read-my-writes, only to find that their underlying data store is eventually consistent. The integration point/API client on our end may end up being twice as complex or more just to handle that.
• yewenjie 5y ago
  Slightly related, what are the most high-quality resources for learning backend engineering?
• Sonata 5y ago
  Having a good knowledge of HTTP is useful in many different contexts. - The correct semantics for each HTTP method - What different status codes indicate - Common headers, particularly around caching - HTTP 1.1 vs HTTP 2 - Common authentication protocols - OAuth 2.0, JWTs, etc.
• Aeolun 5y ago
  Lazy loading Dependency inversion/injection
• agentultra 5y ago
  - HTTP: REST/HATEOAS, headers, transport layer caching, rate limiting, load balancing - Authentication: OAuth2 is probably the most widely used - Authorization: RBAC - Some rudimentary statistics: know how to read metrics, write metrics, etc - Learn one RDBMS inside and out. Other database systems have their place but you’ll almost always encounter a Postgres, MySQL, MSSQL. Learn how to read EXPLAIN output, cursor based pagination, and indices.
• aszen 5y ago
  I have found that the most important bit as a backend engineer is modelling the application domain precisely. A taste for making good APIs helps and knowing how to measure performance. These days most backend engineers also tend to manage data sources so understanding them is also a plus
• koolba 5y ago
  Don’t hide the async nature of external requests. It seems like a magically good idea until it all falls apart. Timeouts and error propagation needs to flow from the request ingress all the way to the backend services.
• corobo 5y ago
  Look into and learn as much as possible about penetration testing. No better way to know how to secure your code than the mindset of "Ok how would I break into this" :)
• bovermyer 5y ago
  Besides all of the excellent suggestions others have said, I would add: - the OSI model, DNS, TCP/UDP, TLS, and networking in general - CPU flame graphs and other low-level performance/debugging tools - the Knightmare devops story - anger management
• Zealotux 5y ago
  I'm currently learning back-end coming from a front-end career, and I started reading "Designing Data-Intensive Applications" by Martin Kleppmann, seems to be a must-have for anyone who wants to get serious in this field.
  • davidkell 5y ago
    +1 For this recommendation, an exceptional book. In particular chapters 2-3 demystify how databases work, and provides an intuition on when to use different kinds of databases and query languages without the typical hype (spoiler alert - use an RDBMS!)
  • humbleMouse 5y ago
    Yes this is a great book and a perfect example of language agnostic knowledge that is useful.
• Diggsey 5y ago
  IME, it's the following considerations that make back-end development hard: - Fault tolerance. - Backwards (or forwards) compatibility. - Scalability. - Testability. - Everything around state (backup/restore, migration strategies, data integrity, etc.) Most other things are a one-time cost. These things are an ongoing burden to consider, but if you forget to consider them it can be devastating. Also remember: any time you give a (internal or external) customer programmatic access to something, that is an API, and APIs have huge costs to maintain. That includes when you dump your database into "data lake" for internal reporting...
• gilfoyle 5y ago
  Would totally recommend this book "Patterns of Enterprise Application Architecture" by Martin Fowler https://martinfowler.com/books/eaa.html https://martinfowler.com/books/eaa.html
• tompazourek 5y ago
  Almost everything is actually language agnostic or transferable. So it's a big question.
• chris_j 5y ago
  Understand the importance of having good visibility of your system. Implement good logging and collect metrics, for example the four golden signals of throughput, latency, saturation and error rate. The Google SRE book gives a good introduction to some of these concepts. See for example https://sre.google/sre-book/monitoring-distributed-systems/ https://sre.google/sre-book/monitoring-distributed-systems/. Understand how to load test your system and to reason about its behaviour under load and its failure modes when you push it too hard. It's one thing to be able to build a system and functionally test it such that you're confident that it behaves correctly when you send one request at a time. It's another thing to let thousands or millions of real users hit it for real in production and to have confidence that you are giving them all a good experience.
• bbkane 5y ago
  I would add soft skills - how to sell your ideas; how to ask for help, how to offer help with offering offense; how to write docs, emails, or proposals; how to avoid taking offense when it feels like you're being ignored or slighted (usually not the case); how to keep stakeholders updated; creating realistic timelines. I'm sure I'm missing some. You can accomplish more than your technically astute colleagues and work on more interesting projects if people trust you, like you, and feel inspired and happy to work with you.
• nogbit 5y ago
  IAM, who and what is authenticating, how and what permissions will it have. What data is coming into your system and it’s variety, velocity and volume. Do you really need NoSQL, probably not. Do you really need that ORM and all the schema, migrations and ops to go with it, known the pros and cons. Are your boundaries defined well? Networking, firewalls etc? Are or do they need to be identity aware? Are you logging what you need to log, where you need to log it and do the right people have access to it? Maybe metrics are really what you need. What’s the dev story like? Can I run things locally or easily without spending days recreating an environment? IAC is one thing, but debugging some Python locally vs deploying and print statements sucks. Have a good readme and leave the repo better than you found it. Tackle the hard problems first, then create reproducible developer story, then hand it off to someone Jr. so they can do the grunt work and you can help them out in a jiff. CI/CD, incrementally improve it over time and don’t spend time boiling the ocean here. A simple bash script to deploy may suffice for an SRE to take it to the next step as IAC or to drop it into some CI tool. Apply the practice of least privilege from the very start. KISS, if what you are building is too confusing, it’s because you need to spend more time writing about it vs actually writing it.
• rasikjain 5y ago
  Here are some of the concepts in no particular order. This is the quick list I came up based on my experience and usage. 1) RDBMS, NoSQL Concepts 2) Writing Queries and Joins 3) Connecting to Database native and ORM 4) HTTP Verbs like POST, GET, DELTE, PUT etc 5) Restful API and GraphQL Concepts 6) Session State, Application State, Caching and Safe Error Handling 7) Distributed Systems, SOA, Async Functions (i.e file handling) 8) Design Patterns, OOPs concepts (Abstraction, Interfaces etc) 9) Authentication, Authorization, Cryptography 10) Configuration, Minimum Privileges (e.g dbrole, server account etc)
• aristofun 5y ago
  Any (almost) software engineering concept is language agnostic. The sooner you get this attitude the more comfortable youll be with your skills development.
• slifin 5y ago
  How to move your IO and side effects to the edge of your system So that you can perform tests without firing the side effects
• stueynz 5y ago
  Privacy management.. Privacy laws are severely restricting who may see people’s PII Are you using the PII data for purposes other than it was originally collected? Can you synthesise a good enough set of test data so you don’t have to anonymise production data? Hint: you can’t sufficiently anonymise production data and still have it be useful
• perelin 5y ago
  I always thought the roadmap.sh Backend Developer Roadmap gives a nice overview of technologies and concepts. Even though it misses some things imo (identity management comes to mind) https://roadmap.sh/backend https://roadmap.sh/backend