Database

• Avoid using nullable fields in your DB. Put not null everywhere you can when defining a table. Assign a default blank value if submitting a field is not necessary:

  create table foo (
    ...
    comment text not null default '',
    count integer not null default 0
  );

• Keep your database migrations in raw *.sql files. Wrap each migration into transaction explicitly putting begin; and at the top of file and commit; at the bottom:

  --
  -- A short comment about what this migration does.
  --
  begin;
  
  update foo set bar = 42 where id = 100500;
  
  alter table baz drop column test;
  
  commit;

• Don't delete anything from your DB. Add deleted boolean flag that is false by default and put AND NOT mytable.deleted in WHERE or JOIN statements:

  select * from foo where not deleted;

  select *.f, *.b
  from foo f
  left join bar b on foo.bar_id = b.id and not b.deleted;

• For each table, add created_at that fixates creation time automatically:

  create table foo (
    ...
    created_at timestamp not null default current_timestamp;
  );

• Once you've got any geographical data (locations, areas, routes), install PostGIS extension without inventing your own "smart" algorithms. They will let you down one Friday evening.

• Postgres is great for full-text searching. Try to deal with standard PostgreSQL capabilities before installing Elastic, Sphinx and related stuff.

• Avoid using ORMs. A small wrapper that parses *.sql files and creates plain functions would be enough.

• Don't use triggers to implement business logic. Such behaviour is quite implicit and difficult to maintain. And business rules change all the time.

• Never use floats for currency. Either use NUMERIC(precision, scale) type or keep your money sums in cents within BIGINT.

• Never use string formatting operator to put parameters into a query. Today, every DB library takes care of quoting them. If you need to pass a table name, (what is impossible to deal with using parameters), declare a list of available names and check it explicitly by occurrence in that list.

Code

• Don't align you code with spaces like it's shown below. Use one space only.

  foo = {
    "short":              1,
    "a-bit-longer":       2,
    "very-very-long-one": 3,
  }

• Write unit tests for both server and UI sides immediately once you've started a new project.

• Classes are not data. Prefer plain data structures like lists and maps over classes. Usually, structures are fast and covers the most of requirements.

• Try to follow functional approach when develop a program. Avoid keeping state where it can be skipped. Separate IO from code that does pure calculations.

Frontend

• Don't use vanilla Javascript. Use such modern technologies as ClojureScript, TypeScrip or Elm to develop without pain in the ass. Consider JS as necessary evil running under the hood to ship your application.

• Don't make SAPs (single page applications). Usually they work poorly, the layout leaks, you cannot open a link in a new window and they break W3C standards.

• Even with Javascript turned off, your client must see important information on their screen.

• Don't make you own widgets to substitute standard ones (inputs, drop-downs, etc).

• Never interrupt a user with alerts, popups, splashes.

• Never claim on AdBlock enabled. It's so ridiculous. It's users choice what software to use when browsing the Internet.

Architecture

• Don't make micro-services. Try to keep the whole codebase within. Run different domains of your application in separate threads as components.

• Queues might help a lot. Don't invent your own message queue facility. Use Rabbit, ZeroMQ or even Redis.

• For message processing, use text format but not binary one. You are not Google with their proto-bufs invented to break down network limitations.

• Writing logs in a file and tailing them via SSH is a mess. Write all the logs into (remote) syslog, either your own one or any third-party one. Syslog brings huge capabilities with logs processing.

• Never commit to master branch directly (set that option in your Git config). Use the simplest Git pipeline you can imagine:

  master -> feature-branch -> commits -> pull request -> review -> merge
  

• JSON is bad for configuring software: lots of braces, lack of comments. Take YAML.

• Don't be afraid of long files. There is no a problem if you can navigate of them quickly. Spreading more and more small files turns a project into a mess. In fact, you only need to setup your editor properly.

Programming languages

• Prefer those languages that could give you a single compiled file as a result of you effort (both binary or bytecode). C-family, Go, Rust, Haskell, Java-family are OK. PHP, Python, Ruby, Perl, JavaScript are less OK.

• Take a look at functional languages even you don't have intentions using them in your daily work.

• You'd better try not modern languages but rather old ones. Smalltalk, Lisp, OCaml would be a great choice.

Workspace

• Keep you desktop free from unused items.

• The more gadgets you need having around the less you are productive. Ideally, you only need your Mac connected to the Internet.

• Use messagers on mobile only except those you need to communicate with your customer. On my desktop, I have only Slask running with my customer's room. Leave Telegram, Skype, WhatsApp or whatever else on you phone and check them rarely.

• Turn off all the notifications on you phone/desktop.

• Try to keep you developing tools simple. Choose text editor like Vim or Emacs over IDE. Work with Git from a command line.

• Don't work in open-space. A room with 3-4 people around is OK.

• Don't read the news. Your friends will warn you if something really important happens.

Communication

• Don't argue on Vim vs Emacs, Python vs Ruby and so on. It looks quite unprofessional.

• If you full of thoughts you want to share with the world, open a blog or write a book. But never argue on them in social networks or messagers.

• Even you are a remote worker, say Hi and Bye every time you've started or finished your work day. Your team should know whether are you at the desk or not.

• Be always polite.

• When you don't know what to say, keep silence.

• Never afraid saying No.

• Read about negotiations.

• Invest time and money in improving your English skills.